Poly-γ-glutamic acid (γ-PGA) is a naturally occurring biopolymer that is mainly produced by microbial fermentation and is widely used in the food, industrial, and medical fields due to its biodegradable, non-toxic, and non-immunogenic properties. At present, the microbial fermentation of γ-PGA is still limited to the levels that can be achieved in the laboratory, and it is not yet produced wholesale at an industrial scale in China. Given the likely development and application of γ-PGA production in the future, this study performed strain selection, including the separation of new γ-PGA producers and genetic mutagenesis and manipulation of the original strains, to obtain microbial strains that could produce γ-PGA by fermentation. These strains were then used to assess the mechanisms of γ-PGA synthesis, as well as the conditions that optimized these mechanisms, including the optimal medium composition (carbon sources, nitrogen sources, metallic ions, etc.) and fermentation factors (temperature, pH, dissolved oxygen, etc.). Fermentation methods, including traditional submerged fermentation and solid-state fermentation with agroindustrial residues, were then examined, as were separation methods, among which the organic solvent-induced precipitation and metal ion-induced precipitation methods were compared and contrasted. Finally, the molecular weight, fermentation cost, separation methods, specific synthesis mechanism, and large-scale production of γ-PGA were discussed, with the aim of providing a theoretical basis for the industrial production and further application of γ-PGA in China.